We will continue to study mechanisms by which the ciliary epithelium, ocular vasculature, and aqueous outflow channels maintain intraocular pressure. The ciliary epithelium will be studied under in vitro conditions of culture and their viability and transport properties characterized. Endogenous humoral and pharmacologic influences upon the turnover of aqueous inflow will be measured by clearance techniques. The mechanism of action of adrenergic drugs on intraocular pressure will be studied. An attempt will be made to isolate adrenergic receptors by pharmacologic, chemical and anatomic techniques. Mediators and mediator pathways associated with ocular irritative response, especially miosis and hyperemia, breakdown of the blood-aqueous barrier and elevated intraocular pressure will be studied.